Pregnancy can bring difficult decisions for women living with epilepsy. One important question is whether antiseizure medications (ASMs) can affect a baby’s growth. New evidence from the international EURAP pregnancy registry adds an important piece to that discussion: poor fetal growth may be another pregnancy outcome to consider when choosing antiseizure treatment.
Importantly, this does not mean women should stop their medication. Uncontrolled seizures, particularly convulsive seizures, can also put both mother and baby at risk. Treatment decisions should be made with a neurologist and obstetrician.
What Are Antiseizure Medications?
Antiseizure medications are medicines used to prevent or control seizures in conditions such as epilepsy. During pregnancy, doctors balance seizure control with potential risks to the developing baby.
Commonly used ASMs include lamotrigine, levetiracetam, carbamazepine, oxcarbazepine, valproate and others. Their pregnancy safety profiles are not identical.
What Is Poor Fetal Growth?
Quick answer: Poor fetal growth means a baby is smaller than expected for its gestational age. Researchers commonly use measures such as birthweight below the 10th percentile, known as small for gestational age (SGA).
Poor fetal growth can have important consequences, which is why researchers are studying factors that may contribute to it.
What Does the New EURAP Study Show?
Quick answer: A 2026 prospective EURAP study analyzed nearly 15,900 offspring exposed to ASMs and found that growth outcomes varied by medication and treatment combination. Polytherapy was associated with greater risk of SGA than monotherapy.
The study included pregnancies enrolled in EURAP between 1999 and 2023 and adjusted its analyses for numerous clinical and demographic factors. Researchers assessed birthweight centile, SGA, severe SGA and low birthweight.
Does the Risk Differ Between Medicines?
Quick answer: Yes. The study found differences between individual ASM monotherapies. Compared with lamotrigine, lower birthweight centiles were observed with topiramate, phenobarbital, oxcarbazepine, carbamazepine, valproic acid and levetiracetam.
| Medication | Finding in 2026 EURAP study |
|---|---|
| Lamotrigine | Reference monotherapy |
| Topiramate | Greater reduction in birthweight centile |
| Phenobarbital | Lower birthweight centile |
| Oxcarbazepine | Lower birthweight centile |
| Carbamazepine | Lower birthweight centile |
| Valproic acid | Lower birthweight centile |
| Levetiracetam | Lower birthweight centile |
These are population-level findings, not predictions for an individual pregnancy.
Why Does Combination Therapy Matter?
Quick answer: Polytherapy means using more than one antiseizure medication. In the EURAP study, offspring exposed to polytherapy had approximately a 50% higher adjusted risk of SGA compared with monotherapy.
The researchers also observed lower birthweight centiles as the number of concomitant ASMs increased. However, some combinations did not show a meaningful difference compared with lamotrigine monotherapy, demonstrating why treatment decisions must be individualized.
What About Topiramate and Valproate?
Quick answer: Both deserve particular attention during pregnancy. Current professional guidance recommends avoiding valproate when clinically feasible because of risks including major congenital malformations and adverse neurodevelopmental outcomes. It also recommends avoiding valproate or topiramate when clinically feasible to reduce the risk of SGA.
This does not mean every person taking these medicines will experience complications. It means their risks should be discussed before conception whenever possible.
Is Lamotrigine or Levetiracetam Safer?
Quick answer: Lamotrigine and levetiracetam are among the ASMs that pregnancy guidelines consider when appropriate, particularly because they generally have more favorable major-malformation profiles than some alternatives. But no medicine should be considered universally “risk-free.”
The choice depends on seizure type, previous response, other health conditions, dose and other medications.
Should You Stop Your Medication During Pregnancy?
Quick answer: No—do not stop an antiseizure medication suddenly without medical advice. Stopping an effective ASM can allow seizures to return, potentially creating serious risks for both mother and fetus.
The AAN/AES/SMFM guideline specifically emphasizes maintaining control of convulsive seizures and exercising caution when changing an effective ASM after pregnancy has already begun.
How Can Pregnancy Risk Be Managed?
Quick answer: Preconception counselling, individualized medication selection, appropriate folic-acid supplementation and regular antenatal monitoring can help doctors manage pregnancy risks.
Useful steps include:
- Discuss pregnancy plans with your neurologist before conception.
- Review the ASM, dose and combination therapy.
- Do not change treatment independently.
- Take folic acid as prescribed; the AAN/AES/SMFM guideline recommends at least 0.4 mg daily before conception and during pregnancy for people with epilepsy taking ASMs.
- Attend regular antenatal appointments.
- Follow your clinician’s recommendations for fetal growth monitoring.
What Does This Mean for Women in India?
Quick answer: Women in India with epilepsy can use the same evidence-based principles: maintain seizure control, plan pregnancy when possible and obtain coordinated neurological and obstetric care.
Indian research has also examined pregnancy outcomes among women with epilepsy, including ASM exposure, reinforcing the importance of specialist pregnancy care.
For women in Delhi, Mumbai, Bengaluru, Hyderabad, Chennai or other Indian cities, the practical priority is not finding a “best” medicine online but obtaining individualized advice from a neurologist and obstetrician.
Antiseizure Medications in Pregnancy: Key Takeaway
The latest evidence shows that fetal growth should be considered alongside congenital malformations and neurodevelopment when evaluating ASM use during pregnancy. Risk varies by medication and combination, and polytherapy may carry greater growth-related risk than monotherapy.
Most importantly, never stop or switch an antiseizure medicine on your own. The safest treatment plan is the one that balances effective seizure control with the lowest appropriate pregnancy risk.
Frequently Asked Questions
Can antiseizure medications affect fetal growth?
Yes. Research has found associations between prenatal ASM exposure and outcomes such as SGA or low birthweight, with risk varying between medicines.
Is topiramate associated with poor fetal growth?
Recent EURAP data found lower birthweight centiles with topiramate compared with lamotrigine monotherapy.
Should I stop my epilepsy medicine if I become pregnant?
No. Speak with your neurologist promptly. Abruptly stopping treatment can cause seizures.
Is lamotrigine safe during pregnancy?
Lamotrigine is considered an important treatment option during pregnancy when clinically appropriate, but individual risks and benefits must be assessed.
Can pregnancy be healthy for women with epilepsy?
Yes. With appropriate planning, medication management and obstetric and neurological monitoring, many women with epilepsy have successful pregnancies.
Conclusion
Pregnancy and epilepsy require careful balancing—not fear. The newest evidence highlights fetal growth as an important consideration when selecting antiseizure treatment, but it does not mean medication should be stopped. Early planning, specialist care and individualized treatment remain the foundation of safer pregnancy management.
